1. Field of the Invention
The present invention relates to data communications, and, more particularly, to efficiency in provisioning, routing and restoration of data communication.
2. Description of the Related Art
A data communications network is the interconnection of two or more communicating entities (i.e., data sources and/or sinks) over one or more data links. A data communications network allows communication between multiple communicating entities over one or more data communications links. High bandwidth applications supported by these networks include streaming video, streaming audio, and large aggregations of voice traffic. In the future, these demands are certain to increase. To meet such demands, an increasingly popular alternative is the use of lightwave communications carried over fiber optic cables. The use of lightwave communications provides several benefits, including high bandwidth, ease of installation, and capacity for future growth.
The synchronous optical network (SONET) protocol is one among those protocols designed to employ an optical infrastructure and is widely employed in voice and data communications networks. SONET is a physical transmission vehicle capable of transmission speeds in the multi-gigabit range, and is defined by a set of electrical as well as optical standards. A similar standard to SONET is the Synchronous Digital Hierarchy (SDH) which is the optical fiber standard predominantly used in Europe. There are only minor differences between the two standards. Accordingly, hereinafter any reference to the term SONET refers to both SDH and SONET networks, unless otherwise noted.
In some networks, network nodes store data which they use for proper operation. In SONET, data between adjacent nodes are transmitted in modules called STS's (synchronous transport signals). Each STS is transmitted on a link at regular time intervals (for example, 125 microseconds). See Bellcore Generic Requirements document GR-253-CORE (Issue 2, December 1995), hereinafter referred to as “SONET Specification,” and incorporated herein by reference for all purposes.
SONET network equipment transmits the STS frames in various paths termed Line, Section, and Path. Referring to FIG. 1, SONET equipment is shown as depicting Section, Line and Path definitions. Path Terminating Equipment 10 is shown coupled to Line Terminating Equipment 20. Line Terminating Equipment 20 is coupled to Section Terminating Equipment 30. In general, the network equipment shown in FIG. 1 includes fiber optic equipment that interfaces with other types of transmission equipment.
When transported, the signals are broken into layers: physical, section, line and path. The layers are hierarchical in nature, with each layer performing a different function. The physical layer addresses the transport of bits across the physical medium. Accordingly, no overhead is associated with the physical layer. The equipment associated with the physical layer converts STS-N signals into optical or electrical SONET signals. The section layer addresses the transport of STS-N frames across the physical medium. The equipment associated with this layer functions to perform framing, scrambling, error monitoring and section-level overhead. Section terminating equipment 30 interprets, modifies and creates section overhead. The line layer addresses transport of path level payloads. The line layer further synchronizes and multiplexes functions for the path layer. Line layer overhead functions to maintain and protect. The overhead is interpreted, modified and created by line terminating equipment 20. The path layer addresses transporting payloads between SONET terminal multiplexing equipment. The path layer maps payloads into formats required by the line layer. The path layer communicates end-to-end with the path overhead with path terminating equipment 10. Generally, network equipment that contains path terminating equipment also contains section and line terminating equipment.
What is needed is a provisioning system and method that provides end-to-end provisioning. Newer routing protocols and delivery methods require data beyond network operations data for a network to function efficiently. Terminating equipment more and more requires access to routing type data.